Color Swatch created using heavy application/diluted application and was applied on cold press watercolor paper (150 lb) material.
This color contains the following pigments:
PG18—Viridian
Pigment Type
inorganic
Chemical Name
chromium(III)-oxide dehydrate
Chemical Formula
Cr2O3 • 2 H2O or Cr2(OH3)
Properties
Viridian is the standard green and is stable, powerful, and cold with an emerald green undertone. It has a transparent hue, good tinting strength, a dark masstone that can be almost black at full strength, and a slow drying time in oil form. Viridian is commonly replaced by the darker, more saturated, and staining Phthalo Greens, but its properties make it a necessary part of the palette of an experienced landscape painter.
Permanence
Viridian has excellent permanence, except in high-temperature work, and is highly valued as a glazing color.
Toxicity
Viridian is slightly toxic.
History
Viridian’s name comes from the Latin viridis, meaning green. The process for manufacturing Viridian, or Transparent Oxide of Chromium, was patented by Guignet in Paris in 1859. However, it had actually been discovered by Pannetier and Binet in 1838. Viridian replaced Verdigris, which was reactive and unstable, and Emerald Green, which was a poisonous copper aceto-arsenite used as a rat poison in the sewers of Paris.
Alternate Names
Emerald Chromium Oxide, Emeraude Green, French Veronese Green, Guignet’s Green, Pannetier's Green, Permanent Green, Smaragd Green, Transparent Oxide of Chromium, Vert Emeraude. Casali's Green and Mittler's Green are varieties of Viridian. Viridian has historically been sold under the name Emerald Green, but they are currently considered to be and are marketed as two different pigments.
PB28—Cobalt Blue
Pigment Type
inorganic
Chemical Name
cobalt(II) oxide + aluminum oxide
Chemical Formula
CoO + Al2O3
Properties
Cobalt blue is a semitransparent pigment with low to moderate tinting strength. When it dries, it appears lighter and less saturated. Pigment particles are large and grainy. Differences in how the pigment is ground and mixed lead to considerable differences in its performance among various manufacturers.
Permanence
Cobalt blue is absolutely lightfast and extraordinarily stable. The stability of cobalt salts at high temperatures make them the standard for blues used in ceramics and glassware.
Toxicity
Cobalt salts are toxic. Avoid respiratory and skin contact. Soluble cobalt may cause irritation and allergic reaction through contact with skin. It is considered a possible carcinogen.
History
Since ancient times, smalt blue has been used to color glass and ceramics. Cobalt salts, which give smalt its characteristic blue color, were identified in the 18th century. Techniques for manufacturing Cobalt Blue, a chemically pure salt of cobalt and aluminum oxide, were developed in 1802.
Alternate Names
Smalt Blue
PW6—Titanium White
Pigment Type
inorganic
Chemical Name
titanium dioxide
Chemical Formula
TiO2
Properties
Titanium White is the most brilliant of the white pigments. It is considered an all purpose oil color useful in all techniques and the best all around white. Its masstone is neither warm nor cool, placing it somewhere between Lead White and Zinc White. It is less prone to cracking and yellowing than Lead White, but it still yellows easily. Titanium White dries slowly in oil form, more slowly than Lead White but more quickly than Zinc White. It is opaque in oil and acrylic forms and semi-opaque in watercolor form. This pigment has good chemical stability, and its tinting strength is superior to both Lead White and Zinc White. It is also the only acrylic white available.
Permanence
Titanium White has excellent permanence and lightfastness.
Toxicity
Titanium dioxide is highly stable and is regarded as completely non-toxic. Animal studies give no indiciation that it is absorbed biologically, even after long periods of exposure. The primary safety concern is with inhalation of fine pigment dust particles. Titanium White, if inhaled in large amounts over the course of several years, may cause a benign pneumoconiosis that is visible on x-rays. The National Institute of Occupational Safety and Health (NIOSH) considers fine titanium dioxide particles, if inhaled, to be a human carcinogen. The primary concern for artists is to avoid exposure to fine particulate dust from raw pigments.
History
Titanium is the ninth most abundant element in the Earth's crust, however mineral deposits that are economical to mine are less common. Titanium dioxide was first discovered in 1821, although it could not be mass produced until 1919. Widespread use of the pigment began in the 1940s. Since that time, it has become the most commonly used white pigment. The name comes from the Latin word Titan, the name for the elder brother of Kronos and ancestor of the Titans, and from the Greek word tito, meaning day or sun.
Alternate Names
None.
